Magnus Maximus vs Rashidun commander Al-Qaqa

Maximus's forces confronted Gratian near Paris. Gratian's army, largely composed of barbarian auxiliaries, deserted him. Gratian fled to Lugdunum (Lyon), where he was captured and executed on Maximus's orders. Maximus then controlled Gaul, Britain, and Spain.

Magnus Maximus, a Roman general of Spanish origin stationed in Britain, was proclaimed emperor by his troops. He crossed to Gaul with a large army, challenging the legitimate Western Emperor Gratian. This act initiated a civil war in the Western Roman Empire.

The Eastern Emperor Theodosius I, unable to immediately challenge Maximus, recognized him as co-emperor in the West. Maximus was granted control of Gaul, Britain, and Spain, while Valentinian II (Gratian's half-brother) retained Italy and Africa. This temporary peace lasted four years.

Maximus invaded Italy, forcing Valentinian II to flee to Theodosius in the East. Theodosius marched west and defeated Maximus's army at the Battle of the Save (modern Sava River in Croatia). Maximus was captured at Aquileia and executed.

Al-Qaqa ibn Amr commanded a cavalry division at the Battle of al-Qadisiyyah against the Sassanid Empire. His tactical maneuvers, including a night attack, helped secure a decisive Arab victory that opened the way for the conquest of Ctesiphon and the fall of the Sassanid capital.

Al-Qaqa ibn Amr participated in the Battle of Yarmouk against the Byzantine Empire. He led a cavalry charge that exploited a gap in the Byzantine lines, contributing to the decisive Arab victory that secured Syria and Palestine for the Rashidun Caliphate.

Al-Qaqa ibn Amr was among the commanders who besieged and captured the Sassanid capital of Ctesiphon. His forces entered the city after the Persian army retreated, leading to the seizure of the royal treasury and the collapse of Sassanid resistance in Mesopotamia.